Captcha support for CakePHP 2.2+

Generates an image with random text alpha|math which requires a human to validate. This is to prevent automated spam and spam bots.

Features:

• Multiple captcha types alpha|math
• Supports rotation of text
• The image width and height dimensions can be set
• The font size can be adjusted
• Random monospace fonts are used during generation anonymous|droidsans|ubuntu
• Multiple captchas allowed per form
• Theme colour profiles default|random|green|red|blue

Demonstration

captcha.baselocker.com

examples (random alpha|math on page load):

   

Requirements

• PHP version: 5.2+
• CakePHP version: 2.0+

Installation

Clone or download the component:

git clone git://github.com/donovan-duplessis/cakephp-captcha.git

Copy the component and behavior into your framework at:

cd cakephp-captcha
cp Controller/Component/CaptchaComponent.php <your-app>/app/Controller/Component/
cp Model/Behavior/CaptchaBehavior.php <your-app>/app/Model/Behavior/

Copy the fonts into your framework at:

cp -R Lib/Fonts <your-app>/app/Lib/
chmod 755 <your-app>/app/Lib/Fonts

GD library needs to be installed for PHP (for dynamic image creation):

Ubuntu

sudo apt-get install php5-gd

Mac OSX (MacPorts)

sudo port install php5-gd

Errors

e.g. "Call to undefined function imagecreatetruecolor ()"

Install php5-gd library as described above

Usage

Include Captcha behavior in model:

public $actsAs = array('Captcha');

Include Captcha component in controller:

public $components = array('Captcha');

To output the captcha image from controller:

$this->Captcha->generate();

Reload image

Refer to sample code (mostly in contacts index view) which refreshes the captcha image via jQuery.

Authentication

If you are using the authentication component, ensure that the captcha action (that generates the image) is granted access.

Sample Code

Model Contact.php

<?php
App::uses('AppModel', 'Model');
class Contact extends AppModel {
    public $actsAs = array(
        'Captcha' => array(
            // We will be handling 2 captcha controls on the form
            'field' => array('captcha', 'captcha-2'),
            'error' => 'Captcha code entered invalid'
        )
    );
}
?>

Controller ContactsController.php

<?php
App::uses('AppController', 'Controller');

class ContactsController extends AppController {

    // Keep track of the two captcha controls, each captcha store/verify
    // will be kept in its own session variable.
    public $captchas = array('captcha', 'captcha-2');

    public $components = array(
        'Captcha' => array(
            'type'   => array('alpha', 'math'),
            'rotate' => true
            'theme'  => 'random'
        ),
        'RequestHandler'
    );

    public function captcha()  {
        $this->autoRender = false;

        // Retrieve the basename for the image route so that we can
        // uniquely identify and generate each captcha control.
        $captcha = basename($this->params['url']['url'], '.jpg');

        /// Generate actual captcha image (each image unique per image route)
        $this->Captcha->generate($captcha);
    }

    public function index() {
        if ($this->RequestHandler->isPost()) {

            // For each captcha control we need to store the captcha value,
            // retreived from the session, in the corresponding model field so
            // that it can be validated.
            foreach($this->captchas as $field) {
                $this->Contact->setCaptcha($field,
                    $this->Captcha->getCode($field));
            };

            $this->Contact->set($this->request->data);

            if ($this->Contact->validates()) {
                $this->Session->setFlash('Captcha codes validated successfully',
                    'flash_good');
            }
        }

        // Store configured captcha controls in view for rendering
        $this->set('captcha_fields', $this->captchas);
    }
}
?>

Route Config/routes.php

Router::connect('/img/captcha.jpg', array('controller' => 'contacts', 'action' => 'captcha'));
Router::connect('/img/captcha-2.jpg', array('controller' => 'contacts', 'action' => 'captcha'));

View Contacts/index.ctp

<?php
    echo $this->Form->create('Contact');
    // For each configured captcha control, render the captcha image +
    // text input element + reload link
    foreach($captcha_fields as $index => $captcha) {
        echo $this->Html->image($captcha . '.jpg', array('id' => $captcha));
        echo $this->Html->link('reload image &#x21bb;', '#', array('class' => 'reload', 'escape' => false));
        echo $this->Form->input($captcha, array('label' => 'Captcha', 'value' => '', 'tabindex' => $index + 1));
    }
    echo $this->Form->end('Submit');
?>

License

• Licensed under The MIT License
• Redistributions of files must retain the above copyright notice.
• http://opensource.org/licenses/MIT

Copyright

Copyright (C) Donovan du Plessis, donovan@binarytrooper.com

Contributors

• Adriano Luís Rocha (ALR), adrianlouis
• Yanosh Kunsh (YLK), yanosh-kunsh

Changelog

1.8 [Jun 25, 2014]

• Add support for theme colour configurations
• Add support for multiple captch types alpha|math

1.7 [Jun 24, 2014]

• Output image data in repsonse body correctly (YLK)

1.6 [Jun 04, 2014]

• Add support for multiple captchas per form (mubasshir request)

1.5 [Aug 05, 2013]

• Add reload captcha image implementation to contacts sample code

1.4 [Jun 19, 2013]

• Add initialize method to component to set correct image response type and body
• Refactor readme document and script comments

1.3 [Oct 25, 2012]

• Set font path to Lib/Fonts (ALR)
• Access Model reference correctly in Behavior (ALR)

1.2 [Oct 17, 2012]

• Set component and behavior to framework 2.0 compliant (ALR)

1.1 [Apr 18, 2012]

• Add character limit configuration to component
• Initial default configuration settings in Behavior
• Refactor code and readme document

1.0 [Mar 29, 2012]

• Initial Version